Vented mechanical device



United States Patent 3,439,963 VENTED MECHANICAL DEVICE Charles E. Hein, Newfield, and James 0. Tennies, Ithaca, N.Y., assignors, by mesne assignments, to Borg-Warner Corporation, Chicago, Ill., a corporation of Delaware Filed Mar. 3, 1967, Ser. No. 620,380 Int. Cl. F16c 1/24, 33/72; F16j /00 US. Cl. 30836.1 1 Claim ABSTRACT OF THE DISCLOSURE This invention relates to a rotational device adapted to be mounted on a shaft wherein a first member is mounted on the shaft and a second member is rotatably mounted on bearings on the first member. The bearings are contained in a lubricant chamber provided by seals that extend from the first to the second member longitudinally beyond the bearings. The first member is provided with two longitudinally spaced annular grooves in the periphery thereof with one groove enclosed under a bearing and the other groove positioned only partially under the bearing. The grooves are interconnected by one longitudinal peripheral slot having a depth less than either of the grooves and being circumferentially spaced from a keyway in the first member. A passage is formed in the first member in the bottom of the enclosed groove at one peripheral point adjacent the keyway and interconnectin the keyway with the enclosed groove.

The figure shows a sprag cam clutch with the novel venting structural arrangement.

A cam clutch generally represented by the numeral 10 is illustrated in the figure for the purpose of describing the invention. The clutch 10 includes, among other things, an inner race member 11, an outer race member 12, sprags 13, bearings 14 and seals 15. The inner race 11 is provided with a shaft passage 16 adapted to receive a drive shaft 17 and a keyway 19 adapted to receive a key 20 supported in the keyway 19 and in the shaft 17 for locking the inner race 11 to the shaft. The bearings 14 are supported on an outer surface of the inner race 11 against shoulders 26 extending radially outward. The outer race 12 is mounted on the bearings 14 and is thereby rotatably mounted on the inner race 11 and is held against longitudinal motion by rings 27 positioned in grooves in the outer race 12. The sprags 13 are positioned between a circumferential surface 30 of the inner race 11 and an internal surface 31 of the outer race 12 that is substantially concentric with the surface 30 of the inner race 11.

The sprags 13 can have any one of many configurations normally utilized in cam clutches and for purposes of illustrating this invention the sprags are of the type which are cammed into engagement with the surfaces 30 and 31 of the inner and outer races to provide a drive therebetween when a load is applied to the outer race 12 and the drive shaft 17 is rotated in one direction but, which will not provide such drive connection when the drive shaft 17 is rotated in the other direction. In the former, the typical drive is provided by a cam clutch as illustrated, and in the latter, there is the typical overruning effect as illustrated. A lubricant (not shown) is provided for the bearings 14 and the sprags 13 and is retained by the seals 15 held in position by retaining casings 32 press fitted or otherwise secured to the inner surface 31 of the outer race 12. It should be noted that the seals 15 provide a bearing and sprag lubricant enclosure 33 for the purpose of retaining the lubricant in the area of the bearings 14 and sprags 13.

The present invention has an improved venting structure in the lubricant enclosure. In particular, the inner race 11 of the clutch 10 has a small passage 34 formed therein interconnecting a groove 35 on the outer surface 25 with a passage such as the keyway 19. The groove 35 is connected to a longitudinally spaced groove 36 in the outer surface 25 of the inner race 11 by a longitudinal slot 37. It should be noted that the slot 37 is substantially circumferentially spaced from the passage 34. Further, the slot 37 is of substantially less depth than either of the grooves 35 or 36.

In the operation of the invention, the drive shaft 17 may be rotated in one direction to provide driving connection between the inner and outer races 11 and 12, or it may be driven in the other direction without a driving connection in an overrunning elfect. In the latter case, the friction in the bearings 14 and other adjacent rotating elements positioned between the inner and outer members will cause the lubricant and the surrounding air in the enclosure 33 to elevate in temperature and expand.

Ordinarily, the expansion of the lubricant in the air in the chamber 33 will tend to force oil between the inner race surface 35 and the seals 15 to cause rupture or leakage of the seals, and eventual loss of lubricant. However, in this invention, expanding air in the enclosure 33 may escape through the inner race by passing through groove 36, slot 37, groove 35, passage 34 and longitudinal passage 19 to the atmosphere to relieve the pressure within the enclosure. Similarly, air may be drawn from the atmosphere into the enclosure when the lubricant and air in the enclosure tend to contract due to cooling off of the clutch during less severe use.

It should be noted that the passage 34 is directed radially inward into the keyway 19 so that centrifugal action during the relative rotation of the inner and outer races 11 and 12 cannot cause lubricant to be forced through the passages 34 and 19. The lubricant will be forced radially outward allowing only air to pass radially inward through the passage 34. Also, inasmuch as the passage 34 is formed in the inner race and extends radially inward and can only vent through the keyway 19 which is not otherwise connected with the chamber 33, lubricant below a certain level in the cam clutch lubricant enclosure 33 will not run out of the enclosure under the force of gravity when the inner race 11 is stopped with the passage 34 in the down position which is opposite to the position shown.

Further, it should be noted that groove 35 in the inner race 11 is positioned entirely under the bearing 14 so that the only lubricant that may pass therein must pass through the slot 37 from the groove 36. The groove 36 is positioned with respect to the bearing 25 so that the outer radial surface thereof is positioned approximately over the center of the groove 36. The slot 37 is of substantially lesser depth than either of the grooves 35 or 36, so that oil passing radially inwardly along the surface of the bearing 25 over the groove 36 will flow into groove 36 to the bottom of the clutch rather than through the slot 37 and out of the clutch through groove 36 and keway 19.

Thus, the present invention is provided with a lubricant enclosure vent by virtue of the novel inner race structure having a longitudinal passage 19, passage 34, groove 35, groove 36 and slot 37.

It is to be understood that the invention is not to be limited to the specific constructions and arrangements shown and described, as it will be understood to those skilled in the art that changes may be made without departing from the principles of the invention.

What is claimed is:

1. A rotational device adapted to be mounted on a keyed shaft comprising a first member having a passage formed therein for receiving the shaft, a second outer member positioned around said first member, bearing means for rotatably supporting said second member on said first member, and seal means extending between said first and second members for enclosing said bearing means between said first and second members, said first member having a keyway formed therein opening into the shaft passage and extending axially to the end of the first member, said first member having first and second longitudinally spaced annular grooves formed in the periphery thereof with the first of said grooves longitudinally positioned entirely under one of. said bearing means and the second of said grooves longitudinally positioned only partially under said bearing means, said first member having a radial passage formed therein in the bottom of said first groove at one peripheral point thereof ad- References Cited UNITED STATES PATENTS 2,217,801 10/1940 Katcher 308l87 2,294,105 8/1942 Wallgren 308-361 2,851,315 9/1958 Zavoda 308187.1 3,320,007 5/1967 Tennies et al 308-l87 3,363,952 1/1968 Paterson 308187.1

MARTIN P. SCHWADRON, Primary Examiner.

L. L. JOHNSON, Assistant Examiner.

US. Cl. X.R. 

